A-LevelBiologyImmunity9700/22 · May/June 2023 · Q310 Marks

Cells of the immune system respond to the presence of non-self antigens.

(a)Outline the features of non-self antigens.[3]
(b)Four different types of cells of the immune system are shown in Table 3.1. Complete Table 3.1: • use a tick (✔) if the description applies to the named cell of the immune system • use a cross (✗) if the description does not apply. [Table 3.1][4]
(c)The cell cycle can be divided into different parts. Complete sentences A, B and C to provide more information about the mitotic cell cycle. A The part of the cell cycle that occurs immediately after mitosis is B The part of the cell cycle in which the S phase occurs is C The main event that occurs during the S phase is[3]

Mark scheme

Marking points from the official mark scheme (May/June 2023). The mark or mark type is shown in brackets.

[1] stimulates an immune response ;
[1] (usually) protein / glycoprotein / polysaccharides ;
[1] recognised by / activates / stimulates, (a named immune system cell) e.g. phagocyte / macrophage / neutrophil / B-/T-lymphocyte / plasma cell ;
[1] cause production of (specific) antibodies / bind to (specific) antibodies ;
[1] example of location of non-self antigen ; e.g. surface of pathogens / infected cells / tumour cells / non-body cells/foreign cells ;
[1] B-lymphocyte: able to go through a number of cell cycles (clonal expansion) (✔) ; main role is to secrete cytokine during an immune response (✗) ; present during a primary immune response to a virus (✔) ;
[1] plasma cell: able to go through a number of cell cycles (clonal expansion) (✗) ; main role is to secrete cytokine during an immune response (✗) ; present during a primary immune response to a virus (✔) ;
[1] T-helper cell: able to go through a number of cell cycles (clonal expansion) (✔) ; main role is to secrete cytokine during an immune response (✔) ; present during a primary immune response to a virus (✔) ;
[1] T-killer cell: able to go through a number of cell cycles (clonal expansion) (✔) ; main role is to secrete cytokine during an immune response (✗) ; present during a primary immune response to a virus (✔) ;
[1] A = cytokinesis ;
[1] B = interphase ;
[1] C = DNA replication ;

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